CMS Detector Performance Summaries

Performance of top triggers in Run 2
/CMS Collaboration
The performance of the triggers used in top physics during the Run 2 is summarized. The document reviews the performance of electron and jets cross-triggers and fully hadronic triggers in the 2016 and 2017 data-taking..CMS-DP-2019-026; CERN-CMS-DP-2019-026.-
Geneva : CERN, 2019 - 13 p. Fulltext:PDF;

Auxiliary material for the 2018 luminosity measurement
/CMS Collaboration
To use the calibration obtained from a van der Meer scan under physics data-taking conditions with more bunches and significantly higher instantaneous luminosity, an additional measurement of the stability and nonlinearity of the luminosity detectors is required. Potential nonlinear effects are important especially during Run 2 (2015-2018), where pileup during physics data taking reached up to about 50. [...] CMS-DP-2019-024; CERN-CMS-DP-2019-024.-
Geneva : CERN, 2019 - 4 p. Fulltext:PDF;

Simulation studies of the impact of the CMS radiation environment on RPC detectors
/CMS Collaboration
The High-Luminosity Large Hadron Collider (HL-LHC) upgrade aims to increase its luminosity by a factor of 5 beyond the LHC's design value and the integrated luminosity by a factor of 10, increasing the potential for discoveries after 2025. The increased collision rate of particles will be a challenge for the CMS systems as higher levels of radiation could degrade them and affect their performance. [...] CMS-DP-2019-023; CERN-CMS-DP-2019-023.-
Geneva : CERN, 2019 - 9 p. Fulltext:PDF;

Results of DT Longevity Studies
/CMS Collaboration
The CMS drift tubes (DT) muon detector, built for standing up the LHC expected integrated and instantaneous luminosities, will be used also in the High Luminosity LHC (HL-LHC) at a 5 times larger instantaneous luminosity and, consequently, much higher levels of radiation, reaching about 10 times the LHC integrated luminosity. Initial irradiation tests of a spare DT chamber at the CERN gamma irradiation facility (GIF++), at large (about O(100)) acceleration factor, showed aging effects resulting in a degradation of the DT cell performance; however, full CMS simulations have shown almost no impact in the muon reconstruction efficiency over the full barrel acceptance and for the full integrated luminosity. [...] CMS-DP-2019-018; CERN-CMS-DP-2019-018.-
Geneva : CERN, 2019 - 11 p. Fulltext:PDF;

CMS ECAL Timing Resolution Performance with Run 2 data
/CMS Collaboration
The CMS electromagnetic calorimeter (ECAL) is made of about 75000 scintillating lead tungstate crystals arranged in a barrel and two endcaps. The scintillation light is read out by avalanche photodiodes in the barrel and vacuum photodiodes in the endcaps, at which point the scintillation pulse is amplified and sampled at 40 MHz by the on-detector electronics [...] CMS-DP-2019-021; CERN-CMS-DP-2019-021.-
Geneva : CERN, 2019 - 8 p. Fulltext:PDF;

Level-1 E/Gamma trigger performance in Run II
/CMS Collaboration
In this note, the performance of the CMS Level-1 E/Gamma trigger during LHC Run II data taking period is presented. The results are obtained using LHC proton-proton collision data recorded by the CMS detector during 2016, 2017 and 2018, at $\mathrm{\sqrt{s}=13 \ TeV}$, corresponding to an integrated luminosity of 35.9 $\mathrm{fb^{-1}}$, 41.3 $\mathrm{fb^{-1}}$ and 58.8 $\mathrm{fb^{-1}}$ respectively..CMS-DP-2019-020; CERN-CMS-DP-2019-020.-
Geneva : CERN, 2019 - 13 p. Fulltext:PDF;

Relative non-linearity of BRIL luminometers derived from CMS mu-scans
/CMS Collaboration
The CMS Beam Radiation Instrumentation and Luminosity Project (BRIL) is devoted to the simulation and measurement of beam conditions and luminosity for CMS. The project is engaged in operating and developing new detectors, compatible with the high luminosity experimental environments at the LHC. [...] CMS-DP-2019-014; CERN-CMS-DP-2019-014.-
Geneva : CERN, 2019 - 7 p. Fulltext:PDF;